One of the rapidly changing aspects of our modern world is the ways in which we can conduct warfare. Lances and swords changed to guns and cannons, to aircraft and today one of the arrows in the quiver of warfare is cyber attack.
Now nation states and other "actors" have the capability to do great harm to systems that we depend on for our daily lives. Listen to this KUOW NPR Radio show on the topic of Cyber Warfare There are rules of war. For instance you are not supposed to shoot at a pilot who has bailed out of an airplane as they are descending to earth via their parachute. But, if it is airborne infantry above you, shoot away! Since their mission will be to kill or capture you when their feet reach the ground. For cyber warfare there aren't any rules--yet...
The issue of "attribution" and who is doing what to who seems to be a thorny problem. How do you retaliate if you can't identify who attacked you? Re-purposing of cyber weapons is something that puts a new twist on picking up the bullets just shot at you and throwing them back at the enemy--whoever that might be. The rules of engagement, what to use, when and how will all have to be thought through. I expect there will be some "trial and error." The error part means someone will probably die because a cyber attack went awry.
We have all heard about collateral damage from aircraft bombing runs. How will that work with cyber warfare? Will it be OK to attack electrical utilities? Who declares "cyber wars?" Life is changing rapidly and our old systems are going to have trouble keeping up with the changes, this includes the ethics of what we can do.
Changing subjects for a moment: For instance in the medical field ethics will be the issue dominating future discussions and decisions. Modern medicine will allow us to do or not do many things we could never do before. The allocation of resources will be hotly debated and the ethics of what we might be able to do "clone?" are not done being decided.